Explosions are dangerous not only because of the shrapnel that may be thrown from the explosion, but also because of the blast wave an explosion generates. The more powerful the explosion the more damaging the blast wave. Blast waves may damage equipment and harm individuals because of the severe pressure differentials that are experienced over an extremely short period of time. In certain explosions, normal atmospheric pressure may rise to over 100 psi and then drop to below −20 psi in less than 2500 microseconds. Under these conditions, severe injury to ears, eyes, and lungs may result.
In certain defense applications, an approximate time of detonation and location of an explosion may be known. For example, a rocket propelled grenade may be intercepted by a rocket fired from a defense system at a relatively safe distance from equipment and personnel. The location and the time of this explosion may therefore be predictable. Although this explosion may occur at a safe distance such that shrapnel may not be propelled far enough to cause significant damage, the blast wave created by this explosion may nevertheless inflict damage to equipment and injury or even death to individuals.